Method and device for frame acknowledgment

ABSTRACT

A method for frame acknowledgement, comprising caching the unacknowledged frame; determining whether a caching capacity threshold is reached; bearing an immediate acknowledgement instruction into a data frame, and sending the data frame the caching capacity threshold is reached; wherein, the immediate acknowledgement instruction is for use in instructing a return acknowledge response of all unacknowledged frames in a specified physical frame period.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 14/008,327 filed on Dec. 3, 2013, now allowed, andtitled “METHOD AND DEVICE FOR FRAME ACKNOWLEDGEMENT” which claimspriority of PCT/CN2012/072895 filed on Mar. 23, 2013, ChineseApplication No. 201210053116.2 filed on Mar. 2, 2012, ChineseApplication No. 201210027919.0 filed on Feb. 8, 2012, ChineseApplication No. 201110189230.3 filed on Jul. 6, 2011, ChineseApplication No. 201110130194.3 filed on May 19, 2011, and ChineseApplication No. 201110081288.6 filed on Mar. 31, 2011, the disclosure ofall are hereby incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

This Invention belongs to the field of wireless communication,especially related to the method and device for the frameacknowledgement.

BACKGROUND OF THE INVENTION

Over the recent years, wireless network technology include the wirelessLAN technique WiFi that is based on the 802.11 standard, the Bluetoothsystem that is based on the 802.15 standard, the Femto technique that isdirected to indoor applications and derived from the mobilecommunication system, etc.

The 802.11-based WiFi technique is currently the most widely usedwireless network transmission technology. It is principally applied towireless local area network environment, application scenarios with roompredominate, may also be applied to an outdoor environment. 802.11system evolves into 802.11a and 802.11g based on OFDM technology forminitial 802.11b CDMA-based transmission mechanism. Although, in thelatest IEEE 802.11n-2009 standard, enabling 802.11n physical peak rateattainable 600 Mbps by introducing multi-antenna (MIMO) technology, buttypically MAC (Media Access Control) layer throughput only reaches tothe maximum of 300 Mbps. So for conventional WLAN systems, MAC layerdesign of a single-user access network based on CSMA/CA (Carrier SenseMultiple Access with Collision Avoidance) is bottleneck of networkperformance. Thus, although existing Wi-Fi techniques provide user withcheap access way to some degree, but is hard to accommodate current andfuture rapid development of high rate multimedia traffic demands.

Femto technique based on 3GPP standard is a kind of new technology forindoor coverage evolved from mobile communication system, Femtotechnique based on 3G system employs CDMA transmission scheme, LTE orWiMAX system-oriented Femto techniques employ OFDM transmission scheme.This multiple access mechanism by time, frequency, codeword allocatedfor different users mutually orthogonal access resource contention, itis substantially different from competition-based CSMA/CA access.However Femto techniques derive from mobile communication systemoriented 3G/LTE/WiMAX system. Since 3G/LTE/WiMAX system primarily applyto wide area coverage mobile communication scenario, systemcharacteristics for short-range wireless communication scenario is notoptimized. Meanwhile, strict requirement of synchronization incomplicated upper layer protocol design and PHY layer based3G/LTE/WiMAX, results in equipment costs that cannot be as cheap as802.11. That is also main reason why Femto technique has not been widelyused at present.

With increasingly rapid development of multimedia service applicationrequirements, in order to meet demand for wireless communication, thereis a need to present a more suitable implementation.

SUMMARY OF THE INVENTION

The technical problem which needs to solve in this Invention is toprovide the method and device for frame acknowledgement, thusefficiently guarantee the successful transmission of data.

This Invention provides a method for frame acknowledgement,characterized in that, comprising:

Bear instant acknowledgement indication in data frame; the mentionedinstant acknowledgement indication is used for indicating instantreturned frame acknowledgement;

Send data frame which carries the mentioned instant acknowledgementindication out.

This Invention provides a device for frame acknowledgement,characterized in that, comprising:

Encapsulation module, it is used for bearing instant acknowledgementindication in data frame; the mentioned instant acknowledgementindication is used for indicating the instant returned frameacknowledgement;

Sending module, used for delivering the data frame of the carriedmentioned instant acknowledgement indication out.

This Invention provides a type of frame acknowledgement method ischaracterized by, including:

Caching the unacknowledged frame;

Determining whether it reaches the caching capacity threshold or not;

Bearing the immediate acknowledgement instruction into a data frame, andsend the data frame when it reaches the caching capacity threshold;

Wherein, the said immediate acknowledgement instruction is for use ininstructing a return acknowledge response of all unacknowledged framesin a specified physical frame period.

This Invention provides a device for frame acknowledgement,characterized in that, comprising:

Caching module, it is used for caching the unacknowledged frame;

Judging module, used for judging whether it has reached caching capacitythreshold;

Encapsulation module, used for bearing instant acknowledgementindication in data frame when it reaches caching capacity threshold; thementioned instant acknowledgement indication is used for indicating areturn acknowledge response of all unacknowledged frames in a specifiedphysical frame period;

Sending module, it is used for delivering the data frame of the carriedmentioned instant acknowledgement indication out.

This Invention, which provides the method and device for frameacknowledgement, can provide a response mode for guaranteeing thesuccessful transmission of data and save transmission resourcesefficiently.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic flow chart of a method for frame acknowledgementaccording to a first embodiment of the invention;

FIG. 2 is a detailed frame format for group acknowledgement frameaccording to a first embodiment of the invention;

FIG. 3 is a detailed frame format for acknowledgement frame according toa second embodiment of the invention;

FIG. 4 is a schematic flow chart of a method for retransmissionaccording to a third embodiment of the invention;

FIG. 5 is a detailed frame format for G-MPDU frame according to a thirdembodiment of the invention;

FIG. 6 is a detailed frame format for G-MPDU subframes according to athird embodiment of the invention;

FIG. 7 is a schematic flow chart of a method for retransmissionaccording to a fourth embodiment of the invention;

FIG. 8 is a detailed frame format for instant acknowledgement requestframe according to a fourth embodiment of the invention;

FIG. 9 is a schematic flow chart of a method for adopting associatedmode to bear the instant acknowledgement request according to a fifthembodiment of the invention;

FIG. 10 is a schematic flow chart of a method for adopting associatedmode to bear the delayed acknowledgement request according to a fifthembodiment of the invention;

FIG. 11 is a schematic flow chart of a method for receiving the delayedacknowledgement request adopted by associated mode according to a fifthembodiment of the invention;

FIG. 12 is a first structural representation of a device for frameacknowledgement according to a fifth embodiment of the invention;

FIG. 13 is a second structural representation of a device for frameacknowledgement according to a fifth embodiment of the invention;

FIG. 14 is a third structural representation of a device for frameacknowledgement according to a fifth embodiment of the invention;

FIG. 15 is a first structural representation of a device for frameacknowledgement according to a sixth embodiment of the invention;

FIG. 16 is a first structural representation of a device for frameacknowledgement according to a seventh embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION The First Embodiment

The embodiment of this Invention provides a method for frameacknowledgement. which is not only suitable for the management frame butalso appropriate for the data frame. After transmitting frame fromtransmitting terminal, the receiving terminal should return anacknowledgement to inform the transmitting terminal whether said datahas been received successfully, then it could carry out an efficientmonitoring of the data transmission.

Refer to the FIG. 1, this figure shows a method for frameacknowledgement in one embodiment of this Invention. It includes thefollowing steps:

Step S101: Encapsulating the acknowledgement of one or multiple framesas Group Acknowledgement (GroupAck);

Wherein, said acknowledgement of the frame is used to instruct thereceiving state of the frame, which includes received and not received.

Step S102: transmitting said group acknowledgement.

The embodiment of this Invention provides a response mode of groupacknowledgement, which is encapsulating multiple frames acknowledgementsto one frame and transmitting. By adopting this response mode, it justneeds to transmit once for the same frame header parameter and it savestransmitting resources efficiently; in addition, when it transmits onthe physical channel, it can get multiple frames' acknowledgements whileimplement the synchronization of one frame (GroupAck), thus to savephysical transmitting resources efficiently.

The wireless communication system supports various services and thetransmission of data is in accordance with service flow. According tothe types, the service flows can be divided into management service flowand data service flow. The management service flow consists of one ormultiple management frames while the data service flow is made up of oneor multiple data frames. Besides, the data services can also be dividedinto more flows according to the detailed service type, such as serviceflow 1 (FID1), service flow 2 (FID2) . . . service flow n (FIDn).

Therefore, step S101 could further include (not shown in the figure):

Step S1011: Encapsulating the acknowledgement of one or multiple framesas Group Acknowledgement;

Step S1012: Encapsulating the acknowledgement of one or multiple serviceflows as Group Acknowledgement.

During encapsulating group acknowledgement, it also needs to encapsulatethe identifiers of said one or multiple service flow and the identifiersof said one or multiple frames on said service flows, so that thereceiving end can identify that the received group acknowledgement isthe acknowledgement of which frames on which service flow.

Preferably, the embodiment of this invention proposes a scheme ofsuccessively bearing the acknowledgement of frames on the service flowby each bit symbol of bitmap and identifying the corresponding frameacknowledgement by the corresponding frame number of bit symbol of saidbitmap. The receiving end will get which frame acknowledgement said bitbear according to the corresponding frame number in bit of said bitmapand get the content of the acknowledgement of the frame identified bysaid bit symbol number on the basis of the value of said bit symbol.

Preferably, to the continuous multiple frame acknowledgements of theservice flow, it can identify the continuous and multiple frameacknowledgements of service flow according to the specific positionframe among the continuous frames, such as the corresponding framenumber of the first bit among bitmaps and the length of bitmaps. Everybit in the bitmap corresponds to one frame acknowledgement.

Preferably, the length of said bitmap is not stable. The returned amountof frame acknowledgements is very flexible, which further improves theresource utilization rate.

Preferably, it also can set fragmentation instruction information toinstruct what the corresponding bitmap bears are fragmentation frameacknowledgement or not. It means the embodiment of this inventionsupports the acknowledgement of both the non fragmentation frames andthe fragmentation frames. At the same time, it can feedback theacknowledgement by blending fragmentation frames and non fragmentationframes. For example, it carries acknowledgement of FID1 and FID0 in thegroup acknowledgement and the frames of FID0 are non fragmentationframes while the frames of FID1 are fragmentation ones. Then the bitmap0will be instructed as the non fragmentation frame acknowledgement ofFID0 and the bitmap1 will be instructed as the fragmentation frameacknowledgement of FID1. For another example, it carries acknowledgementof FID1 and FID0 in the group acknowledgement. FID0 contains nonfragmentation frames and fragmentation frames and the frame of the FID1is non fragmentation. Then bitmap0 will be instructed as the nonfragmentation frame acknowledgement of FID0, bitmap1 will be instructedas the fragmentation frame acknowledgement of FID0 and bitmap2 will beinstructed as the fragmentation frame acknowledgement of FID1.

In order to state it more clearly, the embodiment of this invention alsoprovides a specific form for group acknowledgement frame, as illustratedin FIG. 2. The group acknowledgement frame shown as the FIG. 2 containsframe header, frame body and frame check series message (FCS). The frameheader includes frame control message such as frame types (managementframe or data frame); Subtype (specific management frame types orspecific data frame types), version information etc.; the frame bodycontains one or multiple FID message blocks. Said FID message blocksinclude service flow identification, serial number and bitmap. Saidbitmap is used to bear the continuous multiple frame acknowledgements,and every bit in the bitmap corresponds to one frame acknowledgement.Said serial numbers are used to instruct the corresponding frame numberof the first bit in said bitmap.

Preferably, configuring each FID message block on the basis of thelength of bitmap; said length of bitmap is not constant.

Preferably, assigning the field of bitmap length in said FID messageblock to instruct the length of bitmap.

Preferably, assigning the fragmentation instruction message in said FIDmessage block to instruct what said bitmap bears is the acknowledgementsof fragmentation frames or non fragmentation frames.

Preferably, assigning management control frame acknowledgement bit inthe frame body. to acknowledge one received management control frame ofno serial number.

Preferably, assigning a length field in the frame body to instruct thetotal bytes length of all fields between said length field and FCS fieldwhich is, the sum of length of all the FID message blocks.

The definition of parameters in the frame body can be referred to table1:

TABLE 1 Field Length (Bit) Description Reservation  3 Default setting to0. Management  1 Instructing the acknowledgement Control Frame of areceived management Acknowledgement control frame with no serial bitnumber. Length 12 the total byte length of all fields between saidlength field and FCS field. FID  4 Informing the transmitter that theFID message block is a GroupAck to one FID service flow. SSN 12Informing the transmitter the start numbers of Bitmap of FID messageblock. Bitmap Length  4 Instructing the Bitmap length of each FIDmessage block. 0: 8 bits; 1: 16 bits; 2: 32 bits; 3: 64 bits; 4: 128bits; 5: 256 bits; 6-15: reservation. Reservation  3 Default setting to0. Fragmentation or  1 setting to 1. Instructing the not acknowledgementto the fragmentation data frame. Each bit of Bitmap is making anacknowledgement to one fragmentation of one frame. setting to 0.Instructing the acknowledgement to the non fragmentation data frame.Each bit of Bitmap is making acknowledgement of one frame. Bitmap8/16/32/64/128/256 One bit of Bitmap instructing receiving successfullyor not of some MPDU or fragmentation. If successful, setting to 1.otherwise setting to 0. The serial number of MPDU or fragmentationnumber is calculated according to the SSN and offset.

Said frame acknowledgement is used to instruct the receiving state offrame, which includes received and not received.

Following is the description of the trigger of returning frameacknowledgement in the embodiment of this invention:

1. Immediate Acknowledgement:

Model: immediately returning the acknowledgement frame after receivingthe immediate acknowledgement request.

Said immediate acknowledgement request may be a request frame formatwhich has been agreed on by both sides. Preferably, said immediateacknowledgement request could be the group acknowledgement request whichhas one or multiple service flow identification and one or multipleframe identification of each service flow attached, to instruct animmediate return of the specific frame acknowledge response of specificservice flow. After receiving said group acknowledgement request,returning the specific frame acknowledge response of specific data flowimmediately.

Said immediate acknowledgement request also may be an instructing bitwhich has been agreed on by both sides. For example, setting some fieldof data frame to be the instructing bit for immediate acknowledgement.When analyzing the data frame, if obtaining the immediateacknowledgement instruction in data frame, immediately returning theacknowledgement frame.

Preferably, setting said immediate acknowledgement instruction in theframe header of data frame.

Said immediately returning acknowledgement frame in the embodiment ofthis invention would return in the next time period.

In the embodiment of this invention, center access point (CAP) andstation (STA) could be transmitting end and receiving end mutually.Wherein, CAP is for the entity which provides the access service for theaccessed STA; STA has functional interfaces of media access control(MAC) and physical layer (PHY), it is a terminal equipment which couldcommunicate with CAP. The transmitting end and the receiving end carryout the communication by the physical frame. Each physical frame periodincludes downlink period and uplink period successively: CAP transmitsdata to STA in the downlink period; STA transmits data to CAP in theuplink period. In the embodiment of this invention, when instructing theopposite terminal an immediate return acknowledgement frame; theinstructed immediate return time, which is the next time period, is theuplink physical frame period corresponding to the downlink physicalframe period or the downlink physical frame period corresponding to theuplink period of the last physical frame. Specifically, when thetransmitting end is CAP and it transmits said data frame having theimmediate acknowledgement instruction attached thereto in the downlinkphysical period of the frame, said immediate acknowledgement instructionis used to instruct STA a return frame acknowledge response in theuplink physical period of the frame; when the transmitting end is STAand it transmits the data frame having the immediate acknowledgementinstruction attached thereto in the uplink physical period of the frame,said immediate acknowledgement instruction is used to instruct CAP areturn frame acknowledge response in the downlink physical period of thenext frame.

2. Delayed-ACK

Under the condition of not receiving the immediate acknowledgementrequests, it can be thought it allows a delayed return frame acknowledgeresponse of opposite end.

In the embodiment of this invention, the agreed instruction bit of bothsides distinctly shows the delayed acknowledgement. For example, onefield of the agreed data frame is the delayed acknowledgementinstruction bit. The waiting interval of frame acknowledgement by usingthe delayed-ACK is determined by the transmitting end. It can betransmitted when it has free resource. If it obtains the delayed-ACKinstruction from data frame during analyzing data frame, it will returnthe acknowledgement frame when it has free resource.

The Second Embodiment

To the management control frame, the unicast management frame, which hasno corresponding response frame, needs to acknowledge by using ACK orgroup acknowledgement (GroupAck). Otherwise, it will use correspondingresponse frame acknowledgement directly.

The embodiment of this invention also provides some management requestframe and the corresponding response frame thereof, as shown in theTable 2. Meanwhile, in another embodiment, it also can assign othermanagement request frame and the corresponding response thereofaccording to the requirement. This invention doesn't do any limitationhere.

TABLE 2 Request Frame Corresponding Response Frame Random Access RequestFrame Random Access Response Frame (RA_REQ) (RA_RSP) Terminal BasicCapability Terminal Basic Capability Negotiation Request (SBC_REQ)Negotiation Response (SBC_RSP) Uplink Dynamic Service Access DynamicService Access Response Request (DSA_REQ) (DSA_RSP) Uplink DynamicService Change Dynamic Service Change Response Request (DSC_REQ)(DSC_RSP) Uplink Dynamic Service Delete Dynamic Service Delete ResponseRequest (DSD_REQ) (DSD_RSP) Group Acknowledgement Request GroupAcknowledgement Frame Frame (GroupAckReq) (GroupAck) Sleep Request Frame(SLP_REQ) Sleep Response Frame(SLP_RSP)

All the non-broadcast management control frames (except the randomaccess request response frame and independent resource request frame)need to transmit acknowledgement frame or implied acknowledgement. Theimplied acknowledgement means that the unicast management control frame,which has the corresponding response frame, can regard the responseframe as the acknowledgement frame of this frame. The non-broadcastmanagement control frame doesn't need to acknowledge immediately, theresponse frame just needs to response in the following allowed maximumphysical frame number. If the response frame transmitted by CAP doesn'treceive the acknowledgement frame of STA, it can transmit this responseframe again before it reaches the default maximum retransmission times.When the retransmission times exceed said default maximum times, thetransmitting end will abandon this frame.

Whether the data frame uses immediate acknowledgement or delayedacknowledge is determined by the transmitting end. The receiving end caninstruct whether it needs the immediate acknowledgement or not accordingto the field of instruction frame acknowledgement mode in MAC header.The waiting interval of frame acknowledgement by using the immediateacknowledgement is a time period. The waiting interval of frameacknowledgement by using the delayed acknowledgement is determined bythe transmitting end.

If the acknowledgement mode is immediate acknowledgement and it doesn'treceive the acknowledgement frame in the next time period, this dataframe can be transmitted again before it reaches the default maximumretransmission times. If the retransmission times exceed said defaultmaximum times, the transmitting end will abandon this frame. The nexttime period here said may be the uplink physical frame periodcorresponding to the downlink physical frame period or the downlinkphysical frame period corresponding to the last uplink physical frameperiod. That means when it transmits said data frame having theimmediate acknowledgement instruction attached thereto during thedownlink physical period of this frame, said immediate acknowledgementinstruction is used to instruct a return frame acknowledge response inthe uplink physical period of this frame; when it transmits said dataframe having the immediate acknowledgement instruction attached theretoduring the uplink physical period of this frame, said immediateacknowledgement instruction is used to instruct a return frameacknowledge response in the downlink physical period of this frame. Whenthe MPDU retransmits, the serial number and the fragmentation numberremain unchanged.

If the acknowledgement mode is delayed acknowledgement and it doesn'treceive the acknowledgement frame in the waiting interval which isconfigured by the transmitting end, this data frame can be retransmittedbefore it reaches the default maximum retransmission times. When theretransmission times exceed said default maximum times, the transmittingend will abandon this frame.

There is no need for other frames to acknowledge for ACK frame andGroupAck frame.

To the data frame of fragmentation and non fragmentation, it canacknowledge by using either mode of ACK or GroupAck.

The embodiment of this invention also provides another frameacknowledgement mode (ACK frame). It is suitable for aiming at thesingle frame acknowledgment. In order to state more intuitively, theembodiment of this invention also provides a specific format of theacknowledgement frame, as shown in FIG. 3. The acknowledgement framewhich is shown in FIG. 3 includes frame header, frame body and framecheck series (FCS). The frame header contains frame control message suchas frame type (management frame or data frame), subtype (detailedmanagement frame types or detailed data frame types), and versionmessage etc.; the frame body includes FID, fragmentation serial number(FSN), frame serial number (SN). Each parameter definition in frame bodycan refer to Table 3:

TABLE 3 Length Field (bit) Description Reservation  4 Default setting to0. FID  4 Service flow identification. FSN  4 It means thisacknowledgement is a frame acknowledgement of fragmentation serialnumber FSN. If it doesn't adopt fragmentation, the setting of this fieldwill be 0. SN 12 It means this acknowledgement is a MPDU acknowledgementof SN. If the acknowledged is management control frame of none serialnumber, the SN will be set as 0.

The Third Embodiment

The embodiment of this invention provides a retransmission method, asshown in FIG. 4. It includes the following steps:

Step S401: caching the transmitted frame;

Step S402: receiving and analyzing the frame acknowledge response;

Step S403: retransmitting the cached unacknowledged received frame.

The retransmitted data of the retransmission method provided by theembodiment of this invention is maintained by transmitting end. Duringthe retransmitting, it only retransmits the unacknowledged receivedframe and it will not retransmit the received frame. Especially when itretransmits data according to the default window, it allows to notretransmit the acknowledged and received frame in the window. It savestransmission resource greatly.

Preferably, the acknowledged and received frame in the buffered framecan be deleted so that it can save the local cache efficiently.

Preferably, it can encapsulate one or multiple continuous frames asgroup frame (G-MPDU) and transmit. As shown in FIG. 5, the G-MPDU isconsisted of a series of G-MPDU subframes. As shown in FIG. 6, G-MPDUsubframes contain G-MPDU delimiter, MPDU and probable stuffing bytes.Except for the last G-MPDU subframe, each G-MPDU subframe needs to add0˜1 stuffing byte, making the length of each F-MPDU is the integralmultiple of 2 bytes. Said G-MPDU delimiter is used to localize the MPDUunit of G-MPDU. Encapsulate multiple frames together and transmit, whenit transmits in physical channel it can obtain many frames during thesynchronization of one frame (G-MPDU), then it can save the physicaltransmission resources efficiently.

The received frame acknowledge response in step S402 may be the groupacknowledge response provided in the first embodiment or the singleframe acknowledge response provided in the second embodiment.

The Fourth Embodiment

To the considering of caching capability and prevent the error caused byexceeding caching capability, the embodiment of this invention alsoprovides a method of retransmission, which increases the monitoring ofcaching capability of this terminal. If it detects that the cachingcapability may have any overrunning risks, it will inform the oppositeterminal to return response immediately, which is specifically shown inFIG. 7 and it includes following steps:

Step S701: caching the frames that doesn't receive the acknowledgeresponse;

Step S701: determining whether it reaches the threshold of buffer memorysize;

Step S701: transmitting the immediate acknowledgement request when itreaches the buffer memory size threshold, to instruct an immediatereturn frame acknowledge response.

Preferably, said immediate acknowledgement request has one or multipleservice flow identification, and one or multiple frame identification ineach service flow attached thereto, to instruct an immediate returnacknowledge response of the appointed frame in the appointed data flow.

Preferably, said immediate acknowledgement request can carry the serialnumber of the first frame which needs to return the acknowledgement ineach service flow. It is used to instruct the opposite end a returnframe acknowledge response which starts from said first frame in saidservice flow.

In order to explain it more intuitively, the embodiment of thisinvention also provides a specific frame format of the immediateacknowledgement request, as shown in FIG. 8. The immediateacknowledgement request which is shown in FIG. 8 includes frame header,frame body and frame check series (FCS). The frame header contains framecontrol message such as frame type (management frame or data frame),subtype (detailed management frame type or detailed data frame type),and version message etc.; frame body contains one or multiple FIDmessage blocks. Each FID message block includes service flowidentification FID and serial number. Said serial number means the firstframe serial number which needs to return the acknowledgement in theservice and it is used to instruct the opposite end a return acknowledgeresponse from said first frame. It relates to the corresponding frameserial number of the first bit symbol in bitmap of group acknowledgementwhich is provided by the first embodiment. Each parameter definition offrame body can refer to Table 4:

TABLE 4 Length Field (Bit) Description reservation  4 default setting to0. FID Number  4 Instructing the contained FID message block numbersbetween this field and FCS. FID  4 Requesting the receiving end carryout GroupAck to this FID service flow. SSN 12 Informing the receivingend use this value as the start serial number of Bitmap during GroupAck.

Preferably, the embodiment of this invention also provides anothermethod to realize the immediate acknowledgement: by bearing theimmediate acknowledgement instruction into data frames and transmittingit with data frame together, to transmit immediate acknowledgementrequest; said immediate acknowledgement instruction is used to instructan immediate return frame acknowledge response.

Preferably, it can bear immediate acknowledgement instruction into theframe header of data frame.

Wherein, said immediate return frame acknowledge response is to returnsaid group acknowledge response in the next time period. Said next timeperiod means the uplink physical frame period corresponding to thedownlink physical frame period or the downlink physical frame periodcorresponding to the last uplink physical frame period. That means whenit transmits said data frames having the immediate acknowledgementinstruction attached thereto in the downlink physical period of thisframe, said immediate acknowledgement instruction is used to instructthe opposite end a return frame acknowledge response in the uplinkphysical period of this frame; when it transmits said data framed havingthe immediate acknowledgement instruction attached thereto in the uplinkphysical period of this frame, said immediate acknowledgementinstruction is used to instruct the opposite end a return frameacknowledge response in the downlink physical period of this frame;

Preferably, the embodiment of this invention also can bear the delayedacknowledgement instruction in data frame and transmit with the dataframe before reaching the threshold of the buffer memory size. Saiddelayed acknowledgement instruction is used to instruct that it allowsthe delayed return acknowledge response of all unacknowledged dataframes in each service flow. When the opposite end is analyzing dataframe, if it obtains the delayed acknowledgement instruction from dataframe, it will return the acknowledge response of all unacknowledgedframes in each service flow when it has free resources.

The embodiment of this invention also provides an option of frameacknowledgement transmitting opportunity. Center access point (CAP) andstation (STA) can be transmitting end and receiving end mutually,specifically comprising:

1. If CAP transmits management control frame (needs to acknowledge) toSTA, the CAP needs to reserve resource for acknowledgement frame when itassigns the uplink transmission resources and guarantees STA has chancesto transmit acknowledgement frame successfully.

2. If CAP transmits G-MPDU to STA and instructs STA to carry out theimmediate acknowledgement by the field used to indicate the frameacknowledgement mode, the CAP needs to reserve resources for GroupAckframe or ACK frame when it assigns the uplink transmission resources.

3. If CAP transmits aggregated data frame to STA and instructs to allowthe delayed response of STA by the field used to instruct the frameacknowledgement mode, the STA can transmit GroupAck frame back whenthere is some surplus of uplink transmission resource. It also cantransmit GroupAck back until it receives the information of immediateacknowledgement which is sent by CAP.

4. If STA transmits management control frame (needs to acknowledge) toCAP, the CAP will carry out the acknowledgement in the downlink physicalperiod of next frame.

5. If STA transmits G-MPDU to CAP and instructs CAP to carry out theimmediate acknowledgement by the field used to instruct the frameacknowledgement mode, the CAP will transmit GroupAck frame or ACK framein the downlink physical period of next frame.

6. If STA transmits aggregated data frame to CAP and instructs to allowthe delayed response of CAP by the field used to instruct the frameacknowledgement mode, the CAP can transmit GroupAck frame back whenthere is some surplus of downlink transmission resource. It also cantransmit GroupAck back until it receives the information of immediateacknowledgement which is sent by STA.

The Fifth Embodiment

The embodiment of this invention provides a frame acknowledgementmethod. It adopts associated mode to bear the immediate acknowledgementrequest and requires immediate frame acknowledgement of opposite end, asshown in FIG. 9, and comprises the following steps:

Step S901: bearing immediate acknowledgement instruction to data frame;said immediate acknowledgement instruction is for use in instructing animmediate return frame acknowledge response;

Step S902: transmitting the data frame having said immediateacknowledgement instruction attached thereto.

Preferably, both sides of receiving and transmitting can appoint onefield of data frame as the immediate acknowledgement instruction bit.When transmitting data frame, it requests the opposite end to return theframe acknowledgement immediately by setting said immediateacknowledgement instruction bit. Preferably, it can set immediateacknowledgement instructing bit in the data frame header. Whentransmitting the immediate acknowledgement request, it can instruct theopposite end an immediate return frame acknowledge response by settingthe immediate acknowledgement instruction bit in data frame header.

Preferably, said immediate return frame acknowledge response means toreturn said group acknowledge response in the next time period. Saidnext time period instructs the uplink physical frame periodcorresponding to the downlink physical frame period or the downlinkphysical frame period corresponding to the last uplink physical frameperiod. That means when it transmits said data frames having theimmediate acknowledgement instruction attached thereto in the downlinkphysical period of this frame, said immediate acknowledgementinstruction is used to instruct the opposite end a return frameacknowledge response in the uplink physical period of this frame; whenit transmits said data frames having the immediate acknowledgementinstruction attached thereto in the uplink physical period of thisframe, said immediate acknowledgement instruction is used to instructthe opposite end a return frame acknowledge response in the downlinkphysical period of the next frame;

Preferably, said immediate acknowledgement instruction is used toinstruct a return acknowledge response of all unacknowledged frames sothat the transmission efficiency can be improved and the unnecessarywaste of bandwidth can be reduced.

To the transmitting opportunity of immediate acknowledgement requests,this invention designs to monitor the caching capacity. When it exceedsthe capacity threshold, it will inform the opposite to feedback theframe acknowledge response immediately and to prevent the fault causedby exceeding caching threshold. specifically comprising:

Step 1: caching the frames that doesn't receive the acknowledgement;

Step 2: determining whether it reaches the caching capacity threshold;

Step 3: triggering the transmitting of immediate acknowledgementinstruction before reaching the caching capacity threshold.

The embodiment of this invention also provides a method of frameacknowledgement. It adopts associated mode to bear acknowledgementrequest and informs the opposite to return the frame acknowledgement.Meanwhile it allows the delayed return of opposite end, as shown in FIG.10. It includes the following steps:

Step S1001: bearing the delayed acknowledgement instruction into dataframe; said delayed acknowledgement instruction is used to instruct theallowed delayed return frame acknowledge response;

Step S1002: transmitting the data frame having said delayedacknowledgement instruction attached thereto.

Preferably, both sides of receiving and transmitting can appoint onefield of data frame as the delayed acknowledgement instruction bit. Whentransmitting data frame, it informs the opposite end the allowed delayedreturn frame acknowledge response by setting delayed acknowledgementinstruction bit. Preferably, it can set delayed acknowledgementinstruction bit in the data frame header. When transmitting the delayedacknowledgement request, it can instruct the opposite end a return frameacknowledge response and the allowed delayed return of the opposite endby setting the delayed acknowledgement instructing bit in data frameheader.

Preferably, said delayed acknowledgement instruction is used to instructa return acknowledge response of all unacknowledged frames, so that thetransmission efficiency can be improved and the unnecessary waste ofbandwidth can be reduced.

To the transmitting opportunity of delayed acknowledgement requests,this invention designs to monitor the caching capacity. When it doesn'texceed the capacity threshold, it means it will not exceed the capacityand make error. It is not required to return the frame acknowledgeresponse immediately. Then it needs to guarantee the smooth execution ofthe task for opposite end. Therefore, transmit the delayedacknowledgement instruction and allow the opposite end a delayed returnframe acknowledge response. The detailed steps are as following:

Step 1: caching the frames that don't receive the acknowledge response;

Step 2: determining whether it reaches the caching capacity threshold;

Step 3: triggering the transmitting of delayed acknowledgementinstruction before reaching the caching capacity threshold.

The above two frame acknowledgement methods of this invention considerthe priority of local processing and opposite end service assurance. Itbalances the priority of both sides and improves the whole performanceof system; and it also adopts associated mode to carry out theinstruction. It makes fully use of the present transmission resourcesand reduces the occupied transmission resources which are informed bythe opposite end. At the same time, it is very easy to realize and ithas a high economic value.

Accordingly, the embodiment of this invention also provides a method forframe acknowledgement. It adopts the frame acknowledgement request whichsent by said associated mode in handling, as shown in FIG. 11. The stepsinclude:

Step S1101: receiving the frame;

Step S1102: analyzing the frame header and obtaining the acknowledgementmode;

Step S1103: if the acknowledgement mode is immediate acknowledgement,transmitting the frame acknowledgement in the next time period; if theacknowledgement mode is delayed acknowledgement, transmitting the frameacknowledge response when it has free resources.

Wherein, when receiving frame in the downlink physical period of thisframe and obtaining its acknowledgement mode is immediateacknowledgement, transmit the frame acknowledge response in the uplinkphysical period of this frame; when receiving frame in the uplinkphysical period of this frame and obtaining its acknowledgement mode isimmediate acknowledgement, transmit the frame acknowledge response inthe downlink physical period of the next frame.

Preferably, when one or multiple users receive the immediateacknowledgement instruction in the current time period, the users whoreceived the instruction need to simultaneously transmit frameacknowledge response in the next time period.

In order to realize the above frame acknowledgement method whichrequires the opposite end to carry out the frame acknowledgement, theembodiment of this invention also provides a frame acknowledgementdevice, as shown in FIG. 12. It includes:

Encapsulating module 1201, used for bearing immediate acknowledgementinstruction into a data frame; said immediate acknowledgementinstruction is for use in instructing an immediate return frameacknowledge response;

Transmitting module 1202, used for transmitting the data frames havingsaid immediate acknowledgement instruction attached thereto.

Preferably, said encapsulating module 1201 is used for bearing saidimmediate acknowledgement instruction into the frame header of dataframe.

Preferably, said immediate return frame acknowledgement means totransmit said group acknowledgement in the next time period. Said nexttime period means the uplink physical frame period corresponding to thedownlink physical frame period or the downlink physical frame periodcorresponding to the last uplink physical frame period.

That means when said transmitting module 1202 transmits said data framehaving the immediate acknowledgement instruction attached thereto in thedownlink physical period of this frame, said immediate acknowledgementinstruction is for use in instructing a return frame acknowledgement inthe uplink physical period of this frame. When said transmitting module1202 transmits said data frame having the immediate acknowledgementinstruction attached thereto in the uplink physical period of thisframe, said immediate acknowledgement instruction is for use ininstructing a return frame acknowledgement in the downlink physicalperiod of next frame.

Preferably, said immediate acknowledgement instruction is used forinstructing a return acknowledgement of all unacknowledged frame.

Preferably, it also includes:

Caching module 1203, used for caching the frames that don't receive theacknowledge response;

Determining module 1204, used for determining whether it has reachedcaching capacity threshold or not;

Processing module 1205, used for triggering the transmitting ofimmediate acknowledgement instruction when it reaches caching capacitythreshold.

In order to realize the above frame acknowledgement method that informsthe opposite end to allow the delayed frame acknowledgement, theembodiment of this invention also provides another frame acknowledgementdevice, as shown in FIG. 13. It includes:

Encapsulating module 1301, used for bearing delayed acknowledgementinstruction into a data frame; said delayed acknowledgement instructionis used for instructing the allowed delayed return frameacknowledgement;

Transmitting module 1302, used for transmitting the data frame havingsaid delayed acknowledgement instruction attached thereto.

Preferably, said encapsulating module 1301 is used for bearing saiddelayed acknowledgement instruction into the frame header of data frame.

Preferably, said delayed acknowledgement instruction is used forinstructing a return acknowledge response of all unacknowledged frame.

Preferably, it also includes:

Caching module 1303, used for caching the frames that don't receive theacknowledge response;

Determining module 1304, used for determining whether it has reachedcaching capacity threshold or not;

Processing module 1305, used for triggering the transmitting of delayedacknowledgement instruction when it reaches caching capacity threshold.

In order to realize the above frame acknowledgement method of immediateacknowledgement request which is sent by said associated mode, theembodiment of this invention also provides another device which is usedfor frame acknowledgement, as shown in FIG. 14. It includes:

Receiving module 1401, used for receiving frame;

Analyzing module 1402, used for analyzing the frame header and obtainingthe acknowledgement mode;

Processing module 1403, used for carrying out frame acknowledge responseaccording to the acknowledgment mode. When the acknowledgment mode isimmediate acknowledgment, it transmits frame acknowledge response in thenext time period; if the acknowledgment mode is delayed acknowledgment,it transmits frame acknowledge response when it has free resources.

Preferably, when the acknowledgement mode is immediate acknowledgementand said receiving module 1401 receives said frame in the downlinkphysical period of this frame, said processing module 1403 transmits theframe acknowledge response in the uplink physical period of this frame;if the acknowledgement mode is immediate acknowledgement and saidreceiving module 1401 receives said frame in the uplink physical periodof this frame, said processing module 1403 transmits the frameacknowledge response in the downlink physical period of next frame.

Preferably, to one or multiple users, the received frame acknowledgementmode of whom is immediate acknowledgement in the present time period,said processing module 1403 simultaneously transmits the frameacknowledge response to said users in the next time period.

The Sixth Embodiment

In order to realize the frame acknowledgement method in the embodimentof this invention, this invention also provides a frame acknowledgementdevice, as shown in FIG. 15. It includes:

Encapsulating module 1501, used for encapsulating one or multiple frameacknowledge response to group acknowledgement;

Transmitting module 1502, used for transmitting said group acknowledgeresponse.

Preferably, said encapsulating module 1501 is used for encapsulating oneor multiple frames acknowledge response in the same service flow to theservice flow acknowledge response; encapsulating one or multiple serviceflow acknowledge response to group acknowledge response.

Preferably, said encapsulating module 1501 is used for encapsulating theframe header, frame body and FCS of group acknowledgement: setting oneor multiple FID message blocks in frame body. Said service flowacknowledge response includes service flow identification, serial numberand bitmap. Said bitmap is used for bearing continuous multiple framesacknowledgement. Each bit of bitmap corresponds to one frameacknowledgement. Said serial number is used for instructing thecorresponding frame number of the first bit of said bitmap.

Preferably, said encapsulation module 1501 is used for setting each FIDmessage block according to the length of bitmap; the length of saidbitmap is not constant.

Preferably, said encapsulation module 1501 also assigns the field of thebitmap's length in said FID message block. It is used for instructingthe length of bitmap.

Preferably, said encapsulation module 1501 also sets fragmentationinstructing message in said FID message block. It is used forinstructing the frame acknowledge response bore by said bitmap isfragmentation or non fragmentation.

Preferably, said encapsulation module 1501 also sets management controlframe acknowledgement bit in group acknowledgement. It is used foracknowledging the received management control frame without serialnumber.

Preferably, said encapsulation module 1501 also sets length field inframe body. It is used for instructing the sum of length of all the FIDmessage blocks.

Preferably, said frame acknowledge response is used for instructing thereceiving state of the appointed frame. It includes received and notreceived.

Preferably, it also includes:

The first control module 1504, used for receiving the immediateacknowledgement request, controlling said encapsulating module 1501 toencapsulate the group acknowledge response and controlling saidtransmitting module 1502 to transmit the encapsulated group acknowledgeresponse.

Preferably, said immediate acknowledgement request having one ormultiple service flow identifications and one or multiple frameidentifications attached thereto in each service flow; said firstcontrol module 1504 controls said encapsulating module 1501 toencapsulate the appointed frame acknowledge response in the appointeddata flow to group acknowledge response according to the immediateacknowledgement request.

Preferably, said immediate transmitting means to return said groupacknowledge response in the next time period. Said next time periodmeans the uplink physical frame period corresponding to the downlinkphysical frame period or the downlink physical frame periodcorresponding to the last uplink physical frame period. That means, whenreceiving said immediate acknowledgement request in the downlinkphysical period of this frame, said first control module 1504 controlssaid transmitting module 1502 to transmit the encapsulated groupacknowledge response in the uplink physical period of this frame; whenreceiving said immediate acknowledgement request in the uplink physicalperiod of this frame, said first control module 1504 controls saidtransmitting module 1502 to transmit the encapsulated group acknowledgeresponse in the downlink physical period of next frame.

Preferably, it also includes:

The second control module 1504, used for receiving the data frame havingthe immediate acknowledgement instruction attached thereto, controllingsaid encapsulating module 1501 to encapsulate the group acknowledgeresponse according to the immediate acknowledgement instruction, andcontrolling said transmitting module 1502 to transmit the encapsulatedgroup acknowledge response immediately.

Preferably, said second module 1504, used for controlling saidencapsulation module 1501 to encapsulate the acknowledge response of allunacknowledged frames in each service flow as the group acknowledgeresponse and controlling said transmitting module 1502 to transmit theencapsulated group acknowledge response immediately.

Preferably, said second control module 1504 obtains said immediateacknowledgement instruction by analyzing the frame header of data frame.

Preferably, said immediate transmitting means to return said groupacknowledgement in the next time period. Said next time period means theuplink physical frame period corresponding to the downlink physicalframe period or the downlink physical frame period corresponding to thelast uplink physical frame period. That means, when receiving the dataframes having said immediate acknowledgement instruction attachedthereto in the downlink physical period of this frame, said secondcontrol module 1504 controls said transmitting module 1502 to transmitthe encapsulated group acknowledge response in the uplink physicalperiod of this frame; when receiving the data frames having saidimmediate acknowledgement instruction attached thereto in the uplinkphysical period of this frame, said second control module 1504 controlssaid transmitting module 1502 to transmit the encapsulated groupacknowledge response in the downlink physical period of next frame.

Preferably, it also includes:

The third control module 1505, used for receiving the data frame whichcarries delayed acknowledgement instruction, controlling saidencapsulating module 1501 to encapsulate the group acknowledge responsewhen it has free resources according to the delayed acknowledgementinstruction, and controlling said transmitting module 1502 to transmitthe encapsulated group acknowledge response.

The Seventh Embodiment

In order to realize the frame acknowledgement method in the embodimentof this invention, this invention also provides another frameacknowledgement device, as shown in FIG. 16. It includes:

Encapsulating module 1601, used for generating group acknowledgementrequest. Said group acknowledgement request carries one or multipleservice flow identifications and the frame identification which isneeded to acknowledge in each service flow;

Transmitting module 1602, used for transmitting said groupacknowledgement.

Preferably, the encapsulating module 1601 is used for encapsulatinggroup acknowledgement, and generating said group acknowledgementrequest;

Said group acknowledgement request includes frame header, frame body andFCS. Said frame body includes one or multiple FID message blocks. EachFID message block contains service flow identification FID and serialnumber. It treats the responded first frame serial number in saidservice flow as the acknowledged frame identification and instructs toreturn the frame acknowledgement from said first frame.

Preferably, said encapsulating module 1601 also sets the field of FIDnumber in group acknowledgement request. It is used for instructing theFID message blocks number in frame body.

Preferably, said group acknowledgement request is used for instructingan immediate return acknowledge response of the appointed frame of theappointed data flow.

Preferably, said immediate return group acknowledge response is toreturn said group acknowledge response in the next time period;

Said next time period means the uplink physical frame periodcorresponding to the downlink physical frame period or the downlinkphysical frame period corresponding to the last uplink physical frameperiod. That means when said transmitting module 1602 transmits thegroup acknowledgement request in the downlink physical period of thisframe, said immediate acknowledgement instruction is for use ininstructing a return frame acknowledgement in the uplink physical periodof this frame. When said transmitting module 1602 transmits the groupacknowledgment request in the uplink physical period of this frame, saidimmediate acknowledgement instruction is for use in instructing a returnframe acknowledgement in the downlink physical period of next frame.

What is claimed is:
 1. A method for frame acknowledgement, comprising:caching the unacknowledged frame; determining whether a caching capacitythreshold is reached; bearing an immediate acknowledgement instructioninto a data frame, and sending the data frame the caching capacitythreshold is reached; wherein, the immediate acknowledgement instructionis for use in instructing a return acknowledge response of allunacknowledged frames in a specified physical frame period.
 2. Themethod of claim 1, wherein, bearing the immediate acknowledgementinstruction into the frame header of data frame.
 3. The method of claim1, wherein, transmitting said data frame having the immediateacknowledgement instruction attached thereto in the downlink physicalperiod of this frame; and the immediate acknowledgement instruction isfor use in instructing a return frame acknowledge response in the uplinkphysical period of this frame.
 4. The method of claim 1, wherein,transmitting the data frame having the immediate acknowledgementinstruction attached thereto in the uplink physical period of thisframe; and the immediate acknowledgement instruction is for use ininstructing a return frame acknowledge response in the downlink physicalperiod of next frame.
 5. A device for frame acknowledgement, comprising:caching module, configured to cache an unacknowledged frame; judgingmodule, configured to judge whether a caching capacity threshold isreached; encapsulation module, configured to bear instantacknowledgement indication in data frame when caching capacity thresholdis reached, wherein the instant acknowledgement indication is used toindicate a return acknowledge response of all unacknowledged frames in aspecified physical frame period; and sending module, configured todeliver the data frame of the instant acknowledgement indication out. 6.The device of claim 5, wherein, the encapsulation module bears theinstant acknowledgement indication in the frame header of data frame. 7.The device of claim 5, wherein, the sending module sends the data framewhich carries the instant acknowledgement indication in the downphysical period of this frame; and the instant acknowledgementindication indicates the up physical period returned frameacknowledgement of this frame.
 8. The device of claim 5, wherein, thesending module sends the data frame which carries the instantacknowledgement indication in the up physical period of this frame; andthe instant acknowledgement indication indicates the down physicalperiod returned frame acknowledgement of next frame.